the gastrointestinal effects of parkinsons disease

Difficulty Swallowing
People with Parkinson’s tend to swallow less often and less completely, and as a result some 70 percent have too much saliva, which often pools in their mouth. Sucking on hard candy, preferably sugarless, can stimulate swallowing and provide temporary relief from drooling. An effective treatment, available by prescription, is atropine eye drops taken on or under the tongue. Adjusting anti-Parkinson’s medications may also make it easier to swallow. In addition, medical conditions unrelated to Parkinson’s can lead to difficulty swallowing. Your doctor may image your mouth and throat using a modified barium swallow test to diagnose swallowing difficulties.

Nausea or bloating can result when the stomach empties its contents into the small intestine too slowly, a condition called gastroparesis. It can cause particular problems for people taking levodopa (Sinemet) if the drug remains in the stomach too long and cannot be absorbed by the small intestine and travel to the brain. There is no therapy for gastroparesis; however, different ways of delivering levodopa are being studied, such as skin patches, that would avoid this problem.

Constipation, defined as fewer than three bowel movements per week, is perhaps the most widely recognized gastrointestinal symptom of Parkinson’s disease. Studies have shown that this symptom often begins before motor symptoms are diagnosed. In one study, researchers found that having a bowel movement less often than once a day indicated a risk of developing Parkinson’s four times higher than average.

In some people with Parkinson’s disease, constipation may occur due to the improper functioning of the autonomic nervous system. The autonomic nervous system is responsible for regulating smooth muscle activity. If this system is not working properly, the intestinal tract may operate slowly, causing constipation. Medications used to treat Parkinson’s disease including levodopa, dopamineagonists, amantadine and especially the anticholinergics Artane and Cogentin can also cause constipation. Other causes for constipation include:

Not drinking enough water
A diet low in fiber
Lack of exercise
Travel or other change in routine
Eating large amounts of dairy products
Resisting the urge to have a bowel movement
Antacid medicines containing calcium or aluminum
Other medications (especially strong pain medicines such as opioids, antidepressants, and iron pills)
Medical problems such as irritable bowel syndrome (IBS), diabetes, and colorectal cancer